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Background The in vitro activity of the brown seaweed Dictyota spiralis against both Leishmania amazonensis and Trypanosoma cruzi was evaluated in a previous study. Processing by bio-guided fractionation resulted in the isolation of three active compounds, classified as diterpenes. In the present study, we performed several assays to detect clinical features associated to cell death in L. amazonensis and T. cruzi with the aim to elucidate the mechanism of action of these compounds on parasitic cells. Methods The aims of the experiments were to detect and evaluate specific events involved in apoptosis-like cell death in the kinetoplastid, including DNA condensation, accumulation of reactive oxygen species and changes in ATP concentration, cell permeability and mitochondrial membrane potential, respectively, in treated cells. Results The results demonstrated that the three isolated diterpenes could inhibit the tested parasites by inducing an apoptosis-like cell death. Conclusions These results encourage further investigation on the isolated compounds as potential drug candidates against both L. amazonensis and T. cruzi. Graphical Abstract

Background: The effects of vegetable oils on human health depend on their components. Therefore, their profiles of lipid nutrients and polyphenols were determined. Objective: To establish and compare the fatty acid, tocopherol, phytosterol and polyphenol profiles of Mediterranean oils: cosmetic and dietary argan oils (AO; Morocco: Agadir, Berkane); olive oils (OO; Morocco, Spain, Tunisia); milk thistle seed oils (MTSO; Tunisia: Bizerte, Sousse, Zaghouane); nigella seed oil (NSO). Methods: The biochemical profiles were determined by gas chromatography-flame ionization, high performance liquid chromatography and gas chromatography, coupled with mass spectrometry as required. The antioxidant and cytoprotective activities were evaluated with the KRL (Kit Radicaux Libres) and the fluorescein diacetate tests on nerve cells treated with 7-ketocholesterol (7KC). Results: The fatty acid profile revealed high linoleic acid (C18:2 n-6) content in AO, OO, MTSO and NSO. The highest levels of oleic acid (C18:1 n-9) were found in AO and OO. The tocopherol profile showed that Agadir AO contained the highest amount of α-tocopherol, also present at high level in MTSO and Tunisian OO; Berkane AO was rich in γ-tocopherol. The phytosterol profile indicated that β-sitosterol was predominant in the oils, except AO; spinasterol was only present in AO. Polyphenol profiles underlined that OO was the richest in polyphenols; hydroxytyrosol was only found in OO; few polyphenols were detected in AO. The oils studied have antioxidant activities, and all of them, except NSO, prevented 7KC-induced cell death. The antioxidant characteristics of AO were positively correlated with procatechic acid and compestanol levels. Conclusion: Based on their biochemical profiles, antioxidant and cytoprotective characteristics, AO, OO, and MTSO are potentially beneficial to human health.

Free-living amoebae of genus Acanthamoeba are opportunistic pathogens widely distributed in the environment, and are the causative agents of several humans’ infections, such as Acanthamoeba keratitis, Granulomatous Amoebic Encephalitis and also disseminated infections. The existence of the cyst stage complicates Acanthamoeba therapy as it is highly resistant to antibiotics and physical agents. All these facts reinforced the necessity to find and develop an effective therapy against Acanthamoeba infections. In the present study, we are interested to several seaweeds species collected from the Tunisian coasts and belonging to the 3 phyla (brown, green and red algae). The aim was to quantify the Total Phenolic Compounds in different organic extract, to evaluate antioxidant capacity (DPPH and ABTS) and to study the antiprotozoal activity against A. castellanii Neff. The parasites have been inhibited by all extracts with an IC50 ranged from 52,3±1.8 μg/mL for ethyl acetate extract, to 134,6±0.7 μg/mL for the hexanic one for the various species studied.

Because of the continuous increase in the prevalence of gluten-related disorders, selection of wheat with a low content of immunogenic gluten epitopes could be an innovative alternative for prevention. In this review, the focus is on literature data concerning the deallergenization tools of wheat, which are mainly related to breeding approaches (classic and advanced) and processing operations (germination and fermentation). Until now, no safe wheat genotype has been identified, whereas decreasing wheat allergenicity is possible. On the other hand, the decrease of gluten or some of its epitopes can strongly affect technological properties. Thus, obtaining celiac-safe gluten without affecting the technological properties of wheat could be considered as a new challenge that scientists will be facing. Celiac-safe wheat-based product development could be a great revolution in the market of foods for special medical purposes. The present paper is aiming to: (a) review the strategies and the approaches used, or that can be used, for developing low allergenic wheat: their utilities and limits were also discussed and (b) screen the impact of gluten reduction or removal on the quality of wheat end-use products.

The aim of this study was to compare immunogenic and toxic gluten peptides related to celiac disease (CD). 100 accessions of genotypes selected during the 20th century in Tunisia were in vitro digested and then analyzed by UPLC/ESI-MS technique using an isotopically labeled internal standard. The first MANOVA confirmed a high variability in the content of immunogenic and toxic peptides reflecting high genetic diversity in the germplasm released during the past century in Tunisia, consistently with PCA and clustering analysis results. Our finding showed also important variability in CD epitopes due to growing season's climate scenarios. Moreover, the second MANOVA revealed significant differences between abandoned and modern cultivars' CD-related peptide amounts. Although we could not conclude that there was an augment of allergens in newly selected durum wheat lines compared to abandoned ones, we demonstrated that modern genotype peptides were less sensitive to climate variation, which is a useful indicator for wheat breeders.

Plants are a source of bioactive compounds such as antioxidants and enzyme inhibitors. In this work, effect of the Eucalyptus globulus and Mentha viridis extraction by different solvents on phenolics content, flavonoids content, condensed tannins content, antioxidant activity and inhibitory effect against two lipases from Aspergillus niger and olive was studied. Methanolic (MeOH) extract showed the strongest antioxidant and anti-lipase activities. High correlation between total phenolics content, total flavonoids content, antioxidant activity and lipases inhibitory action was observed. Kinetic analysis of lipases inhibition was performed with Linweaver-Burk, Dixon and Cornish-Bowden plots. These results revealed competitive inhibition mode by E. globulus and non competitive mixed inhibition mode by M. viridis against the two lipases. Inhibition constant (KI) values calculated with E. globulus MeOH extract were 0.271 and 0.188 mg/mL for Aspergillus niger and olive lipases respectively. With M. viridis MeOH extract KI values were 0.303 and 0.421 mg/mL for the fungal and the plant lipases respectively. The inhibitory concentration 50% (IC50) values determined with E. globulus MeOH extract were 0.69 mg/mL for Aspergillus niger lipase and 1.29 mg/mL for olive lipase. With M. viridis MeOH extract IC50 were 0.43 and 1.44 mg/mL for Aspergillus niger and olive lipases respectively.

The Asteraceae family is economically very important, because many of these plants are grown mainly for their food value, such as lettuce (Lactuca), chicory (Cichorium), and sunflower (Heliantus aminus). One of the typical properties of this family, which includes milk thistle (Sylibum marianum), is the richness of the oil in various compounds (flavonoids, alkaloids, tocopherols, and unsaturated fatty acids). Currently, and for the coming decades, age-related diseases, including neurodegenerative diseases, are a major public health problem. Preventing their appearance or opposing their evolution is a major objective. In this context, the cytoprotective activities of milk thistle seed oil produced in Tunisia were studied on the 158N model using 7-ketocholesterol (7KC) and 24S-hydroxycholesterol (24S) as cytotoxic agents. 7KC and 24S were used because they can be increased in the brain and body fluids of patients with major age-related neurodegenerative diseases, such as Alzheimer&rsquo, s and Parkinson&rsquo, s diseases. In order to evaluate the cytoprotective properties of milk thistle seed oil, complementary techniques of microscopy, flow cytometry, and biochemistry were used. The chemical composition of milk thistle seed oil has also been determined by various chromatography techniques. Milk thistle seed oils from different area of Tunisia are rich in tocopherols and are strongly antioxidant according to various biochemical tests (KRL (Kit Radicaux Libres), FRAP (Ferric Reducing Antioxidant Power), and DPPH (2,2-diphenyl-1-picrylhydrazyl)). The main fatty acids are linoleic acid (C18:2 n-6) and oleic acid (C18:1 n-9). The main polyphenols identified are homovanillic acid, p-coumaric acid, quercetin, and apigenin, with a predominance of vanillic acid. On 158N cells, milk thistle seed oil attenuates the cytotoxicity of 7KC and 24S including: loss of cell adhesion, increased plasma membrane permeability, mitochondrial dysfunction, overproduction of reactive oxygen species, induction of apoptosis, and autophagy. The attenuation of the cytotoxicity of 7KC and 24S observed with the milk thistle seed oil is in the order of that observed with &alpha, tocopherol used as a positive control. In the presence of nigella seed oil, considered potentially cytotoxic, no cytoprotective effects were observed. Given the chemical characteristics, antioxidant properties, and cytoprotective activities of milk thistle seed oil, our results highlight the potential benefit of this oil for human health.

Baker's asthma is a serious airway disease triggered by wheat protein CM3 α-amylase/trypsin inhibitor. The purpose of the present study was to investigate the impact of genotype and crop year on allergen CM3 α-amylase/trypsin inhibitor associated with baker's asthma. A historical series of Tunisian durum wheat (100 accessions), derived from three crop years, was used to compare the amount of CM3 from landraces to advanced cultivars. CM3 protein quantification was assessed after an enzymatic cleavage of the soluble protein extracts on a UPLC/ESI-MS system, using a marker peptide for its quantification. Combined data analysis of variance revealed an important effect of genotype, crop year, and their interaction. The CM3 allergenic proteins were found to significantly vary among studied genotypes, as confirmed by genetic variability, coefficient of variance, heritability, and genetic advance.

International audience; Increased levels of 7-ketocholesterol (7KC), which results mainly from cholesterol auto-oxidation, are often found in the plasma and/or cerebrospinal fluid of patients with neurodegenerative diseases and might contribute to activation of microglial cells involved in neurodegeneration. As major cellular dysfunctions are induced by 7KC, it is important to identify molecules able to impair its side effects. Since consumption of olive and argan oils, and fish is important in the Mediterranean diet, the aim of the study was to determine the ability of oleic acid (OA), a major compound of olive and argan oil, and docosahexaenoic acid (DHA) present in fatty fishes, such as sardines, to attenuate 7KC-induced cytotoxic effects. Since elaidic acid (EA), the trans isomer of OA, can be found in hydrogenated cooking oils and fried foods, its effects on 7KC-induced cytotoxicity were also determined. In murine microglial BV-2 cells, 7KC induces cell growth inhibition, mitochondrial dysfunctions, reactive oxygen species overproduction and lipid peroxidation, increased plasma membrane permeability and fluidity, nuclei condensation and/or fragmentation and caspase-3 activation, which are apoptotic characteristics, and an increased LC3-II/LC3-I ratio, which is a criterion of autophagy. 7KC is therefore a potent inducer of oxiapoptophagy (OXIdation + APOPTOsis + autoPHAGY) on BV-2 cells. OA and EA, but not DHA, also favor the accumulation of lipid droplets revealed with Masson's trichrome, Oil Red O, and Nile Red staining. The cytotoxicity of 7KC was strongly attenuated by OA and DHA. Protective effects were also observed with EA. However, 7KC-induced caspase-3 activation was less attenuated with EA. Different effects of OA and EA on autophagy were also observed. In addition, EA (but not OA) increased plasma membrane fluidity, and only OA (but not EA) was able to prevent the 7KC-induced increase in plasma membrane fluidity. Thus, in BV-2 microglial cells, the principal fatty acids of the Mediterranean diet (OA, DHA) were able to attenuate the major toxic effects of 7KC, thus reinforcing the interest of natural compounds present in the Mediterranean diet to prevent the development of neurodegenerative diseases.

In this study, milk thistle seeds growing in different areas in Tunisia were cold pressed and the extracted oils were examined for their chemical and antioxidant properties. The major fatty acids were linoleic acid (C18:2) (57.0%, 60.0%, and 60.3% for the milk thistle seed oils native to Bizerte, Zaghouan and Sousse, respectively) and oleic acid (C18:1) (15.5%, 21.5%, and 22.4% for the milk thistle seed oils originating from Bizerte, Zaghouan and Sousse, respectively). High performance liquid chromatography (HPLC) analysis showed the richness of the milk thistle seed oils (MTSO) in α-tocopherol. The highest content was recorded for that of the region of Zaghouan (286.22 mg/kg). The total phenolic contents (TPC) of Zaghouan, Bizerte, and Sousse were 1.59, 8.12, and 4.73 Gallic Acid Equivalent (GAE) mg/g, respectively. Three phenolic acids were also identified (vanillic, p-coumaric, and silybine), with a predominance of the vanillic acid. The highest value was recorded for the Zaghouan milk thistle seed oil (83 mg/100 g). Differences in outcomes between regions may be due to climatic differences in areas. Zaghouan’s cold-pressed milk thistle seed oil had a better quality than those of Bizerte and Sousse, and can be considered as a valuable source for new multi-purpose products or by-products for industrial, cosmetic, and pharmaceutical utilization.

Therapy against Acanthamoeba infections such as Granulomatous Amoebic Encephalitis (GAE) and Acanthamoeba Keratitis (AK), remains as an issue to be solved due to the existence of a cyst stage which is highly resistant to most chemical and physical agents. Recently, the activity of Olive Leaf Extracts (OLE) was demonstrated against Acanthamoeba species. However, the molecules involved in this activity were not identified and/or evaluated. Therefore, the aim of this study was to evaluate the activity of the main molecules which are present in OLE and secondly to study their mechanism of action in Acanthamoeba. Among the tested molecules, the observed activities ranged from an IC50 of 6.59 in the case of apigenine to an IC50 > 100 μg/ml for other molecules. After that, elucidation of the mechanism of action of these molecules was evaluated by the detection of changes in the phosphatidylserine (PS) exposure, the permeability of the plasma membrane, the mitochondrial membrane potential and the ATP levels in the treated cells. Vanillic, syringic and ursolic acids induced the higher permeabilization of the plasma membrane. Nevertheless, the mitochondrial membrane was altered by all tested molecules which were also able to decrease the ATP levels to less than 50% in IC90 treated cells after 24 h. Therefore, all the molecules tested in this study could be considered as a future therapeutic alternative against Acanthamoeba spp. Further studies are needed in order to establish the true potential of these molecules against these emerging opportunistic pathogenic protozoa.